Fuel cells are cells that convert chemical energy to electric energy directly, and have advantages of high efficiency, low pollution, and low noise, etc. Fuel cells can be individual fuel cells or fuel cell packs comprising a plurality of individual fuel cells.
An individual fuel cell comprises an integral membrane electrode, which usually comprises a proton exchange membrane, two catalyst layers on two sides of said proton exchange membrane, and two diffusion layers on said two catalyst layers respectively.
CN 1437280A discloses a method for producing fuel cells by treating the electrolyte membrane with a solvent, comprising the steps of: immersing the electrolyte membrane of fuel cells in a highly volatile mono-alcohol solvent (e.g., ethyl alcohol) for a certain time, and then immersing the electrolyte membrane in a low volatile poly-alcohol solvent (e.g., ethylene glycol or propylene glycol) for a certain time, to swell the electrolyte membrane sufficiently; coating the catalyst slurry on two sides of the electrolyte membrane; holding the electrolyte membrane coated with catalyst between two diffusion layers, and hot pressing them. Said method coats the catalyst slurry onto the surface of the electrolyte membrane directly and thereby it is difficult to uniformly coat the catalyst thereon. As a result, the catalyst layer of the prepared membrane electrode may have an uneven thickness and an uneven surface.